The present invention relates to a process for producing a fluorine-containing alkylsulfonylaminoethyl α-substituted acrylate represented by the general formula [3], which is useful as a monomer for a next-generation photoresist:
where R1 is a hydrogen atom, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tertbutyl group, fluoromethyl group, difluoromethyl group, trifluoromethyl group or perfluoroethyl group; and R2 is a fluorine-containing alkyl group having a carbon number of 1 to 6.
Sulfonylaminoethyl α-substituted acrylates are expected to be useful as monomers for next-generation photoresists. Photoresist materials, when synthesized using sulfonylaminoethyl α-substituted acrylates as photoresist monomers, are provided with excellent light transparency and surface adsorptivity as reported in U.S. Pat. No. 6,165,678 (hereinafter referred to as “Patent Document 1”). In Patent Document 1, however, there is no detailed description about the synthesis of a fluorine-containing alkylsulfonylaminoethyl α-substituted acrylate represented by the formula [3], which is a target compound of the present invention. Patent Document 1 merely discloses a process for synthesizing a sulfonylaminoethyl α-substituted acrylate in a broad sense by condensation of the corresponding sulfonylaminoethanol with α-substituted acryloyl chloride. It is further reported in Japanese Laid-Open Patent Publication 2005-281301 (hereinafter referred to as “Patent Document 2”) that the synthesis process of Patent Document 1 is not suitable for the synthesis of a fluorine-containing alkylsulfonylaminoethyl α-substituted acrylate.
As a solution to the above problem, Patent Document 2 proposes a process for synthesizing a fluorine-containing alkylsulfonylaminoethyl α-substituted acrylate of the formula [3] by reacting an aminoethyl α-substituted acrylate or salt thereof with a fluorine-containing alkylsulfonic halide or fluorine-containing alkylsulfonic anhydride, as indicated in the following scheme, using acetonitrile as a reaction solvent.
Further, U.S. Pat. No. 6,949,325 (hereinafter referred to as “Patent Document 3”) proposes a process for synthesizing a fluorine-containing alkylsulfonylaminoethyl α-substituted acrylate by reaction of a fluorine-containing alkylsulfonic chloride and an aminoethyl α-substituted acrylate using methylene chloride as a reaction solvent as indicated in the following scheme.
